Abstract
We present a lattice QCD calculation of the , decay amplitude and , the measure of direct violation in decay, improving our 2015 calculation [1] of these quantities. Both calculations were performed with physical kinematics on a lattice with an inverse lattice spacing of . However, the current calculation includes nearly 4 times the statistics and numerous technical improvements allowing us to more reliably isolate the ground state and more accurately relate the lattice operators to those defined in the standard model. We find and , where the errors are statistical and systematic, respectively. The former agrees well with the experimental result . These results for can be combined with our earlier lattice calculation of [2] to obtain , where the third error represents omitted isospin breaking effects, and . The first agrees well with the experimental result of . A comparison of the second with the observed ratio , demonstrates the standard model origin of this “ rule” enhancement.
5 More- Received 18 May 2020
- Accepted 13 August 2020
DOI:https://doi.org/10.1103/PhysRevD.102.054509
Published by the American Physical Society under the terms of the Creative Commons Attribution 4.0 International license. Further distribution of this work must maintain attribution to the author(s) and the published article’s title, journal citation, and DOI. Funded by SCOAP3.
Published by the American Physical Society
Physics Subject Headings (PhySH)
synopsis
Kaon Decays Reevaluated
Published 17 September 2020
A rigorous calculation of a matter-antimatter asymmetry in kaon decays has twice the precision of a previous calculation, removing tension that had existed between theory and experiment.
See more in Physics